Fluid inkjet systems typically include one or more printheads having a plurality of inkjets from which drops of fluid are ejected towards a recording medium. The inkjets of a printhead receive ink from an ink supply chamber or manifold in the printhead which, in turn, receives ink from a source, such as a melted ink reservoir or an ink cartridge. Each inkjet includes a channel having one end in fluid communication with the ink supply manifold. The other end of the ink channel has an orifice or nozzle for ejecting drops of ink. The nozzles of the inkjets may be formed in an aperture or nozzle plate that has openings corresponding to the nozzles of the inkjets.
During operation, drop ejecting signals activate actuators in the inkjets to expel drops of fluid from the inkjet nozzles onto a recording medium. By selectively activating the actuators of the inkjets to eject drops as the recording medium and/or printhead assembly are moved relative to one another, the deposited drops can be precisely patterned to form particular text and graphic images on the recording medium. An example of a full width array printhead is described in U.S. Patent Application Publication No. 2009/0046125, the entire disclosure of which is hereby incorporated by reference herein. An example of an ultra-violet (UV) curable gel ink that can be jetted in such a printhead is described in U.S. Patent Application Publication No. 2007/0123606, the entire disclosure of which is hereby incorporated by reference herein. An example of a solid ink that can be jetted in such a printhead is the Xerox ColorQube™ cyan solid ink available from Xerox Corporation. U.S. Pat. No. 5,867,189, the entire disclosure of which is hereby incorporated by reference herein, describes an inkjet printhead including an ink ejecting component that incorporates an electropolished ink-contacting or orifice surface on the outlet side of the printhead.
Difficulties encountered with fluid inkjet systems include wetting, drooling, and flooding of inks onto the printhead front face. In addition, high ink adhesion of the front face causes ink adhering to the front face. Even with wiping, residue may remain and cause contamination. This contamination of the printhead front face can cause or contribute to blocking of the inkjet nozzles and channels, which alone or in combination with the wetted, contaminated front face can cause or contribute to non-firing or missing drops, undersized or otherwise wrong-sized drops, satellites, or misdirected drops on the recording medium and thus result in degraded print quality.
Maintenance procedures have been implemented in inkjet printers for preventing and clearing inkjet blockages and for cleaning the printhead front face. A maintenance procedure for inkjet printers is described in U.S. Patent Application Publication No. 2008/0316247, the entire disclosure of which is hereby incorporated by reference herein. Examples of maintenance procedures include jetting or purging ink from the inkjet channels and nozzles and wiping the printhead front face. Jetting procedures typically involve ejecting a plurality of drops from each inkjet in order to clear contaminants from the jets. Purging procedures typically involve applying an air pressure pulse to the ink reservoir to cause ink flow from all of the jets. The jetted ink may be collected in a waste reservoir such as a spittoon. The purged ink may be collected in a waste reservoir such as a waster tray. A printhead front face with high ink adhesion can be wetted and contaminated by jetted or purged ink, which may interfere with the collecting of the purged ink by preventing or reducing the ability of the ink to slide over the front face into the waste reservoir. Wiping procedures are usually performed by a wiper blade that moves relative to the nozzle plate to remove ink residue, as well as any paper, dust, or other debris that has collected on the printhead front face. An example of a wiper assembly is described in U.S. Pat. No. 5,432,539, the entire disclosure of which is hereby incorporated by reference herein. Jetting/purging and wiping procedures may each be performed alone or in conjunction with one another. For example, a wiping procedure may be performed after ink is purged through the jets to wipe excess ink from the nozzle plate.
Various coating materials have been proposed for printhead front faces. These coating materials may exhibit one or more advantageous properties, such as anti-weeping, anti-drooling, anti-flooding, anti-contamination, and easy-clean, self-clean properties. While currently available coatings for inkjet printhead front faces are suitable for their intended purposes, it is challenging to form a uniform, micron thick coating on a printhead front face using conventional coating technologies, such as sputtering, dipping, flowing, and chemical vapor deposition without partially or completely covering or clogging the nozzles.
The appropriate components and process aspects of each of the foregoing U.S. Patents and Patent Application Publications may be selected for the present disclosure in embodiments thereof. Further, throughout this application, various publications, patents, and published patent applications are referred to by an identifying citation. The disclosures of the publications, patents, and published patent applications referenced in this application are hereby incorporated by reference into the present disclosure.